(1). Field of the Invention
This invention relates to deep well pumps of the type normally employed to pump oil from wells.
(2). Description of the Prior Art
Prior structures of this type have utilized pistons for displacing the liquid and piston pumps have been known in the art including the use of check valves. See for example U.S. Pat. Nos. 969,127, Pat. No. 2,383,934 and U.S. Pat. No. 411,680.